<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>系统登录页面</title>
</head>
<style>
    html {-webkit-filter: grayscale(100%);filter:progid:DXImageTransform.Microsoft.BasicImage(graysale=1);}
</style>
<body>
<h2>登录页面</h2>
</body>
</html>